Combined spark-plug and spark-gap.



W. C. BRUNKE.

COMBINED SPARK PLUG AND SPARK GAP.

APPLICATION FILED JUNE 25. I917.

Patented Sept. 25, 1917.

auuemboz tion of soot at the inner,

onion.

@liliLl'fiB-Ed G. BBUNKE, F OMAHA, NEBRASKA, ASSIGNQR TO EFFICIENCY M01301- DEVICE CORPORATION, OF OMAHA, NEBRASKA.

COMBINED SPARK-PLUG AND STARK-GAP.

; lilwhum it may concern:

c it lmown that l, lNII-LEAM'G. Banana, an of the United States, residing in the county ofDouglas and raslra, have invented certain new and l improvements in Combined and Spark-Gaps, of which the follcwing is a specification,

This invention relates to a combined spark. and spark gap, and has for one of its oiojects to provide an intensifier for a spark which will include a metallic threaded part for the base of its insulating dome for a mounting on the ground electrode to avoid. the usual formation of threads in the dome. Another object is to provide a mounting for the central electrode which will permit convenient assemblage of parts, will conduce to convenience in manufacture and will prevent any movement of gases through the spark plug without the use of gaskets. Arr other object is to provide an adequate support for sustaining stresses when pressing the tapered central electrode to its seat.

-" Still another object is to provide'an aimular chamber in combination with a tapered electrode of such form that theignited charges of hydrocarbon will prevent any accuinulaexposed, base of the tapered central electrode, to prevent short circuits of the electrical charges.

With the foregoing objects in View the invention presents a novel construction combination and arrangement of parts as de scribed herein and claimed, and as illustrated in the accompanying drawing, wherein,

Figure 1 is a view of the' device in side elevation. Fig. 2 is a view of the same in longitudinal section. Fig. 3 is a transverse section on line 3'3 of Fig. 4. Fig. 5 is a side view, partl in section', of the dome. Fig. 6 is a side view partly in section, of the insulating jacket. Fig. 7 is a side view of the central electrode. Fig. 8 is a plan view of the metallic, threaded base of the insulating dome, its uprigh" flange being in trans verse section. Fig. 9 is a transverse section through the metallic base of the dome.

Referring now to the drawing for a more particular description, the conventional me tallic housing or ground electrode for the spark plug is indicated at 10, the usual cylindrical chamber opening on its inner end being indicated at 11.

Specification of Letters Patent.

Patented Sept. 25, 191%.

Application filed. June 25, 1191?. Serial No. 176,665.

At 12 is indicated a dome constructed of insulating material, provided midway between its top and bottom with sight apertures 13, and having embedded therein, near its top, a metallic reinforcing-block 14;, said block being for the purpose of providing a threaded connection with a comparatively short metallic rod or electrical conductor 15, the block having a threaded aperture, and the upper part of the dome having suitable apertures for receiving said conductor. T he metallic housing is provided at its inner end with an upright, exteriorly threaded, annular flange 16, and therefore forms a recess, circular in plan, indicated at 17. The lower end of the dome is provided with an interiorly threaded metallic base or nut 18 adapted to be mounted on the flange 16, said base being provided with an upright annular flange '19 having apertures 20 formed therein and at the time of molding the dome the insulating material of the dome becomes embedded in the apertures 20 i as a holding means so that the metallic base and dome will be firmly connected; and it will be noted that the required threaded connections for the dome, mentioned, are metallic parts, this being a desired feature of construction since, otherwise, the insulating material employed would soon become worn and the dome would be subject to vibration during operation.

Numeral 21 indicates a tapered metallic electrode circumscribed throughout its en- 'tire length by an insulating jacket 22 of mica, its end of greatest diameter provided with a projection 23, said taperedelectrode having a length greater than the housing 10 and its flange 16, and having a suflicient length to project within the dome, its end of greatest diameter being disposed adjacent to the open end of the chamber 11, said housing 10 being provided with a tapered base for receiving said electrode and its jacket. The projection for the ground electrode for cooperation with the projection 23 as indicated at a.

At 2d is indicated a tapered sleeve or hollow cylinder of insulating material adapted to be disposed to circumscribe the upper ends of the electrode 21 and its mica jacket. Nu; meral 25 indicates a metallic nut having a threaded connection with the end of the electrode 21, and in effect, operating as an electrical conductor therefor.

I When assembling the parts the nut 25 may be rotated to cause a pressure of the electrode 21 and its mica jacket within the tapered aperture of the housing so that no gaskets will be required for preventing an outward movement of gas from the engine I and provlding 'a very rigidmounting forv this electrode for resisting stresses occasioned by the ignited charges of gas during operation, the mica jacket 22 being depended upon for'insulation.

It will be seen that the truncated hollow cone or tapered sleeve 24 bears upon the in-' ma be seen.

11 account of the tapered form of the electrode2l and its jacket 22, in'con unction with the form of the cylindrical chamber ll it will'be seen that when the parts are assembled, an annular space is formed between the jacket and the adjacent wall of the ground electrode said annular space having a greater volume at the inner end of the chamber 11 than at the outer end of the acket, and this is desirable to prevent an accumulation of soot in said annular space nd particularly at the end of the jacket, to ire- 'vent short circuits. It is considered that,

a centrally of and ersmg the plug,

during operation, each ignition of gas will cause the exhaust gases to move outwardly of the chamber 11 with greater force than ordinary on account 0 the constricted part a adjacent-to the en of the jacket which prevents the soot from adhering to the end of the electrode 21. p

Having fully described my invention, what I claim and desire to secure by Letters Patent is.: i 1. In devices for the purposes described, an elongated, metallic plug having a cylindrical chamber opening on its outer end and an annular flange projecting beyond its inner end, a tapered electrode longitudinally travits part of greater divergence belngdisposed in said chamber and its part of lesser divergence being disposed rojecting beyond the end of said annular ange, an insulating jacket disposed within :said. plug and circumscribing the electrode, a. tapered insulating-sleeve mounted on the plug and circumscribing the insulating jacket, an electrical conductor 1 bearing on the'insulatin sleeveand having 1 a threaded connection wlth the electrode, an

insulating dome having sight-apertures in its sides and having a metallic base for a threaded connection with the annular flange of said plug, and an 'electrical conductor mounted}for-longitudinal adjustments in the dome to provide a spark gap substantially in line with the sight-apertures of said dome.

2. In devices for the purposes described, an elongated, metallic plug having drical chamber opening on one 0 its ends a 'cylin-' and having. an annular flange projecting beyond' its opposite end, a tapered insulated electrode longitudinally traversing the plug, its part of greater divergence being disposed in said chamber and its part of lesser. diverjecting beyond the end of said annular flange, a tapered insulating-sleeve mounted on the plug and circumscribing the insulated electrode, a metallic part bearing on the insulating sleeve and havin a'threaded connection with the insulatec electrode, an insulating dome having sight-apertures and having a metallic base for a threaded con-- nection with the annular flange of said plug, and an electrical conductor mounted in thedome to provide a spark gap adjacent to the sight-apertures of said dome;

3. In devices for the purposes described, a metallic plug having a cylindrical chamber opening on one of its ends and having an annular flange projecting beyond its opposite end, a tapered electrode longitudinally traversing.-the plug, its part of greater divergence being disposed in said chamber and its part of lesser divergence centrally of and projecting beyond the end of said annular flange, an insulating jacket disposed within said plug and circulnscrib ing the electrode, an insulating-sleeve mounted on the plug and circumscribing the insulating jacket, a metallic element bearing on the insulating sleeve and having a threaded connection with the electrode, a dome provided with a sightaperture and having a part threaded on the annular flange of ,said plug, and an insulated electrical conductor mounted for longitudinal adjustments in the dome to provide a spark gap in combination with the metallic element on' said insulating sleeve, said spark gap being disposed adjacent to the sight-aperture of the dome.

In testimony whereof I have aflixed my signature in presence of two witnesses.

WVILLIAM C, BRUNKE.

Witnesses:

ARTHUR H. STURGES, HIRABI A. STURGES.

being disposed gence being disposed centrally of and pro- 

